Maybe it’s the brain-curdling heat: South Florida produces some of the most consistently dark and funny crime fiction in the nation, from John D. MacDonald and Elmore Leonard through Carl Hiaasen and, now, John Dufresne. “No Regrets, Coyote,” the Dania Beach-based author’s fifth novel, is not a straightforward whodunit, not even by Florida standards. But as Dufresne follows the haphazard detecting work of protagonist Wyle “Coyote” Melville, he touches on issues of life, death, family, and the craziness of those living on the edge.

“No Regrets, Coyote” opens with a classic setup. Melville has been called to a crime scene where one Chafin Halliday has seemingly killed his family before shooting himself. Only our hero is not a conventional detective. He’s a divorced therapist with commitment issues who has an ability to empathize so strongly he can often experience what others are feeling. This allows him to see beyond the surface of a crime and make out both the causes and the clues for what doesn’t seem quite right. Needless to say, something is off about the Halliday murder-suicide, and Melville spends the rest of the novel getting to the bottom of it, as he also deals with his declining father, sibling issues, an ex-wife, an ex-girlfriend, and a magician best friend who makes a living at poker.

If that sounds like a lot, it is. Dufresne has never been known for straightforward plotting, and each of the minor characters here is rich in quirky detail. (The father, for example, has Alzheimer’s and a desire to see the northern lights before he dies.) Some of this is familiar territory for Dufresne, who has mined a similar Southern Gothic weirdness and the comic and tragic potential of family dysfunction for such novels as “Louisiana Power & Light” and “Requiem, Mass” as well as his numerous short stories. Here, however, he adds the kind of crime-solving element and grim humor that might be more associated with Hiaasen or the great Charles Willeford (whom he name-checks). As soon as you read the murdered family’s name, for example, you expect the inevitable “Halliday on ice” joke, and some of the other chuckles — like the evangelical stripper who calls herself a “Holy Hottie” — are almost Florida crime-fiction staples. But many of the lines rise above even this exalted bar, making their point through grammar and usage as much as detail. Melville’s father, for example, shows how disjointed his sense of time has become, saying “I fell out of bed one night. And a week before that I fell out again.” And a murderer reveals his callousness through the details he chooses to confess: “I hit her with a twelve-inch cast-iron frying pan. A lot.” Dufresne may be playing in a genre pool, but he hasn’t relinquished his literary tools to do so.

Ultimately, that may hurt this book a little. Dufresne’s previous novels tend to have loose structures, and the conventions of crime fiction go only so far to correct that tendency in this outing. Although the clues, in classic crime-fiction style, are pretty much all there from the beginning, Dufresne seems to lose interest in them. As the Halliday case — and Melville’s life — begin to unravel, so does the story-telling. Melville figures out what really happened at that crime scene in time for all the loose ends to converge. And while they do, with some satisfyingly grisly violence — involving in turn an ice pick, a bomb-carrying dog, and an armed paraglider — the revelations still feel a little unearned, as if the author just needed to bring the adventure to a close. What does remain, however, are those idiosyncratic characters and the author’s marvelous voice. Who did what doesn’t matter. How they talk about it, does.